CVE-2026-72382: Linux kernel · ksmbd: reject undersized DACLs before parsing ACEs
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 8.8 High · fixed in d020e7f27bf65eecd3805404702f716b2b6d9e73 : patch Linux kernel soon.
Data as of 30 Oct 2026, 12:49 UTC
Thin evidence
One scorer or none| CNA (Linux) | CVSS 3.1 | 8.8 |
|---|
- Patch
- Available – fixed in d020e7f27bf65eecd3805404702f716b2b6d9e73, 282847c0cf22f2e961155ac8e42f6eeab7e16049, 60908f7ebcd9b6cde74ad5711fab0f49c7970949 +3
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 15 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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Description
In the Linux kernel, the following vulnerability has been resolved: ksmbd: reject undersized DACLs before parsing ACEs parse_dacl() limits the attacker-controlled ACE count by comparing it with the number of minimal ACEs that fit in the DACL size. The DACL size field is 16 bits, but the expression subtracts sizeof(struct smb_acl). Because sizeof() is unsigned, a DACL size smaller than the ACL header underflows to a large size_t. A malicious client can reach this with: SMB2_SET_INFO (InfoType=SMB2_O_INFO_SECURITY) -> smb2_set_info_sec() -> set_info_sec() -> parse_sec_desc() -> parse_dacl() -> init_acl_state(..., 0xffff) -> init_acl_state(..., 0xffff) -> kmalloc_objs(..., 0xffff) Thus a malformed security descriptor can make num_aces pass the guard and drive large temporary ACL state and pointer-array allocations. Reject DACLs smaller than struct smb_acl before doing the subtraction, so the ACE count check cannot be bypassed by the underflow.
References
- git.kernel.org/stable/c/8dc949061e35427433feac3ebe5ec089f2aa857e (opens in a new tab)
- git.kernel.org/stable/c/16fb65ec15fe7c90f50a2115854bfd9a032d4023 (opens in a new tab)
- git.kernel.org/stable/c/282847c0cf22f2e961155ac8e42f6eeab7e16049 (opens in a new tab)
- git.kernel.org/stable/c/d020e7f27bf65eecd3805404702f716b2b6d9e73 (opens in a new tab)
- git.kernel.org/stable/c/15a9e9b8f7f5d7f380ae54c6f5bcbc0bdcb0f3cd (opens in a new tab)
- git.kernel.org/stable/c/60908f7ebcd9b6cde74ad5711fab0f49c7970949 (opens in a new tab)